Nontyphoidal Salmonella enterica strains with a nonclassical quinolone resistance phenotype were isolated from patients returning from Thailand or Malaysia to Finland. A total of 10 isolates of seven serovars were studied in detail, all of which had reduced susceptibility (MIC > 0.125 g/ml) to ciprofloxacin but were either susceptible or showed only low-level resistance (MIC < 32 g/ml) to nalidixic acid. Phenotypic characterization included susceptibility testing by the agar dilution method and investigation of efflux activity. Genotypic characterization included the screening of mutations in the quinolone resistance-determining regions (QRDR) of gyrA, gyrB, parC, and parE by PCR and denaturing high-pressure liquid chromatography and the amplification of plasmid-mediated quinolone resistance (PMQR) genes qnrA, qnrB, qnrS, qnrD, aac(6)-Ib-cr, and qepA by PCR. PMQR was confirmed by plasmid analysis, Southern hybridization, and plasmid transfer. No mutations in the QRDRs of gyrA, gyrB, parC, or parE were detected with the exception of a Thr57-Ser substitution within ParC seen in all but the S. enterica serovar Typhimurium strains. The qnrA and qnrS genes were the only PMQR determinants detected. Plasmids carrying qnr alleles were transferable in vitro, and the resistance phenotype was reproducible in Escherichia coli DH5␣ transformants. These data demonstrate the emergence of a highly mobile qnr genotype that, in the absence of mutation within topoisomerase genes, confers the nontypical quinolone resistance phenotype in S. enterica isolates. The qnr resistance mechanism enables bacteria to survive elevated quinolone concentrations, and therefore, strains carrying qnr alleles may be able to expand during fluoroquinolone treatment. This is of concern since nonclassical quinolone resistance is plasmid mediated and therefore mobilizable.

The in vitro activity of azithromycin against 1,237 nontyphoidal Salmonella enterica isolates collected from Finnish patients between 2003 and 2008 was investigated. Only 24 (1.9%) of the isolates tested and 15 (5.1%) of the 294 isolates with reduced fluoroquinolone susceptibility had azithromycin MICs of >32 g/ml. These data show that azithromycin has good in vitro activity against nontyphoidal S. enterica, and thus, it may be a good candidate for clinical treatment studies of salmonellosis.Salmonella is one of the most common causes of food-borne illnesses and a major cause of human infections all over the world (23). Salmonella infections are usually treated with fluoroquinolones or extended-spectrum cephalosporins. Unfortunately, excessive use of fluoroquinolones both in human and in veterinary medicine has led to increasing numbers of resistant isolates, including nontyphoidal strains of Salmonella enterica (18,19,28). In addition, the nonclassical quinolone resistance phenotype (the Qnr phenotype), showing reduced susceptibility to ciprofloxacin (MIC of Ն0.125 g/ml) but susceptibility or only low-level resistance to nalidixic acid (MIC of Յ32 g/ml), has become more common (6,14,19,20,22). Extended-spectrum ␤-lactamase (ESBL) producers have emerged in Enterobacteriaceae and in Salmonella, and there are reports of the coappearance of ESBL and qnr genes in the same transferable genetic elements (5,10,21,27). These resistance problems may jeopardize the treatment of severe Salmonella infections. Thus, alternative antibiotics for the treatment of Salmonella infections are needed.Salmonella isolates are intrinsically resistant to erythromycin via active efflux (2) but naturally susceptible to azithromycin (29), which is a 15-membered erythromycin derivative. Resistance to macrolides is usually conferred by mutations in nucleotides A2058 and A2059 of the 23S rRNA, according to the Escherichia coli numbering (26). Also, the alteration of the 50S ribosomal subunit proteins L4 (rlpD) and L22 (rlpV) may lead to macrolide resistance (4).The purpose of the present study was to determine the in vitro activity of azithromycin against nontyphoidal Salmonella isolates collected between 2003 and 2008 from Finnish patients. Special attention was paid to isolates with reduced fluoroquinolone susceptibility or showing the Qnr phenotype. In addition, mutations in the 23S rRNA and in the L4 and L22 ribosomal proteins were investigated. A total of 1,237 nontyphoidal Salmonella isolates (638 domestic and 599 foreign) collected from Finnish patients between 2003 and 2008 were included in this study. Starting in January each year, we collected the first 100 domestic and the first 100 foreign, i.e., collected from Finnish travelers returning from abroad, Salmonella isolates. The strains were serotyped at the National Salmonella Reference Centre in Finland.The MICs of antimicrobial agents for the isolates were determined by the agar dilution method according to the CLSI guidelines (8). Mueller-Hinton II agar (Becton Dickinson, Cockeys...

No abstract

Bacterial infections, especially by antimicrobial resistant (AMR) bacteria, are an increasing problem worldwide. AMR is especially a problem with health care-associated infections due to bacteria in hospital environments being easily transferred from patient to patient and from patient to environment, and thus, solutions to prevent bacterial transmission are needed. Hand washing is an effective tool for preventing bacterial infections, but other approaches such as nanoparticle-coated surfaces are also needed. In the current study, direct and indirect liquid flame spray (LFS) method was used to produce silver nanoparticle-coated surfaces. The antimicrobial properties of these nanoparticle surfaces were evaluated with the “touch test” method against Escherichia coli and Staphylococcus aureus. It was shown in this study that in glass samples one silver nanoparticle-coating cycle can inhibit E. coli growth, whereas at least two coating cycles were needed to inhibit S. aureus growth. Silver nanoparticle-coated polyethylene (PE) and PE terephthalate samples did not inhibit bacterial growth as effectively as glass samples: three nanoparticle-coating cycles were needed to inhibit E. coli growth, and more than 30 coating cycles were needed until S. aureus growth was inhibited. To conclude, with the LFS method, it is possible to produce nanostructured large-area antibacterial surfaces which show antibacterial effect against clinically relevant pathogens. Results indicate that the use of silver nanoparticle surfaces in hospital environments could prevent health care-associated infections in vivo.

Respiratory viruses cause seasonal epidemics every year. Several respiratory pathogens are circulating simultaneously and typical symptoms of different respiratory infections are alike, meaning it is challenging to identify and diagnose different respiratory pathogens based on symptoms alone. mariPOC® is an automated, multianalyte antigen test which allows the rapid detection of nine respiratory infection pathogens [influenza A and B viruses, respiratory syncytial virus (RSV), human metapneumovirus, adenovirus, parainfluenza 1-3 viruses and pneumococci] from a single nasopharyngeal swab or aspirate samples, and, in addition, can be linked to laboratory information systems. During the study period from November 2010 to June 2014, a total of 22,485 multianalyte respi tests were performed in the 14 participating laboratories in Finland and, in total, 6897 positive analyte results were recorded. Of the tested samples, 25 % were positive for one respiratory pathogen, with RSV (9.8 %) and influenza A virus (7.2 %) being the most common findings, and 0.65 % of the samples were multivirus-positive. Only small geographical variations in seasonal epidemics occurred. Our results show that the mariPOC® multianalyte respi test allows simultaneous detection of several respiratory pathogens in real time. The results are reliable and give the clinician a picture of the current epidemiological situation, thus minimising guesswork.